Pregnancy in carriers of high-affinity hemoglobins

Pregnancy in female carriers of abnormal hemoglobins with great avidity for oxygen provides a unique opportunity to assess the importance of the usual difference in oxygen affinity between fetal and maternal blood. Outcome of pregnancy was recorded for carriers of hemoglobins Bethesda, Osler, and Yakima, whose p50s (9.5, 9.1, and 12 mm Hg at pH 7.4) were far lower than that of a normal fetus (23 mm Hg at pH 7.3). Neither spontaneous abortions nor intrauterine growth retardation could be attributed to the presence of high oxygen affinity in the mothers. In vitro simulations suggested that neither maternal or fetal polycythemia alone was sufficient to adjust for perturbation of the normal situation, and increased uterine and/or fetal blood flow probably provided additional compensation.

Thermal mapping of the airways in humans

To characterize the intrathoracic thermal events that occur during breathing in humans, we developed a flexible probe (OD 1.4 mm) containing multiple thermistors evenly spaced over 30.2 cm, that could be inserted into the tracheobronchial tree with a fiberoptic bronchoscope. With this device we simultaneously recorded the airstream temperature at six points from the trachea to beyond the subsegmental bronchi in six normal subjects while they breathed ambient and frigid air at multiple levels of ventilation (VE). During quiet breathing of room air the average temperature ranged from 32.0 +/- 0.05 degrees C in the upper trachea to 35.5 +/- 0.3 degrees C in the subsegmental bronchi. As ventilation was increased, the temperature along the airways progressively decreased, and at a VE of 100+ 1/min the temperature at the above two sites fell to 29.2 +/- 0.5 and 33.9 +/- 0.8 degrees C, respectively. Interval points were intermediate between these extremes. With cold air, the changes were considerably more profound. During quiet breathing, local temperatures approximated those recorded in the maximum VE room-air trial, and at maximum VE, the temperatures in the proximal and distal airways were 20.5 +/- 0.6 and 31.6 +/- 1.2 degrees C, respectively. During expiration, the temperature along the airways progressively decreased as the air flowed from the periphery of the lung to the mouth: the more the cooling during inspiration, the lower the temperature during expiration. These data demonstrate that in the course of conditioning inspired air the intrathoracic and intrapulmonic airways undergo profound thermal changes that extend well into the periphery of the lung.

Thermal mapping of the airways in humans

To characterize the intrathoracic thermal events that occur during breathing in humans, we developed a flexible probe (OD 1.4 mm) containing multiple thermistors evenly spaced over 30.2 cm, that could be inserted into the tracheobronchial tree with a fiberoptic bronchoscope. With this device we simultaneously recorded the airstream temperature at six points from the trachea to beyond the subsegmental bronchi in six normal subjects while they breathed ambient and frigid air at multiple levels of ventilation (VE). During quiet breathing of room air the average temperature ranged from 32.0 +/- 0.05 degrees C in the upper trachea to 35.5 +/- 0.3 degrees C in the subsegmental bronchi. As ventilation was increased, the temperature along the airways progressively decreased, and at a VE of 100+ 1/min the temperature at the above two sites fell to 29.2 +/- 0.5 and 33.9 +/- 0.8 degrees C, respectively. Interval points were intermediate between these extremes. With cold air, the changes were considerably more profound. During quiet breathing, local temperatures approximated those recorded in the maximum VE room-air trial, and at maximum VE, the temperatures in the proximal and distal airways were 20.5 +/- 0.6 and 31.6 +/- 1.2 degrees C, respectively. During expiration, the temperature along the airways progressively decreased as the air flowed from the periphery of the lung to the mouth: the more the cooling during inspiration, the lower the temperature during expiration. These data demonstrate that in the course of conditioning inspired air the intrathoracic and intrapulmonic airways undergo profound thermal changes that extend well into the periphery of the lung.

Influence of cromolyn sodium on airway temperature in normal subjects

It is well established that cromolyn sodium attenuates the bronchoconstriction induced by airway cooling in both normal and asthmatic subjects. To determine whether this protection derives from a modification of the thermal events that transpire during the conditioning of inspired air, we first recorded the effect of cromolyn on the bronchoconstrictor response to hyperventilation with frigid air in 7 normal subjects. On a separate occasion, we imposed the same thermal burden and measured the temperature at multiple sites within the airways before and after pretreatment with cromolyn. The first cold air challenge produced a significant decrease in forced expiratory volume in one second (FEV1) of 5.5 +/- 0.9% (SEM) and these changes were significantly reduced by cromolyn (FEV1 = 2.8 +/- 0.9%; p less than 0.05). In concert with the improvement in mechanics, the temperatures (T) within the trachea (tr) and the anterior segment of the right lower lobe (AS-RLL) were significantly higher after cromolyn (Ttr = 1.3 +/- 0.2 degrees C; p less than 0.01; TAS-RLL = 1.0 +/- 0.4 degrees C; p = 0.05), and there was a direct positive relationship between the mechanical protection offered by the drug and the increase in airway temperature (Spearman's rank correlation coefficient = 0.83; p = 0.05). These data suggest that cromolyn modifies respiratory heat exchange in such a fashion as to limit airway cooling. The mechanism of this action is not presently known but may reflect a direct or indirect influence on the bronchial vasculature.

Carcinoid tumour secreting dopa

A middle aged woman referred for an abdominal mass was found to have large amounts of dopa (3-4-dihydroxyphenylalanine) metabolites in her urine. At operation a tumour affecting almost the entire left lobe of the liver was removed. Histologically the tumour was a metastatic carcinoid. After operation the excretion of dopa metabolites fell substantially, confirming that the tumour was the source. Apparently, owing to an enzyme defect the tumour had been unable to decarboxylate dopa. These findings are further evidence of a neural origin for the endocrine system of the gut.

Cognitive impairments in Parkinson's disease: distinguishing between effort-demanding and automatic cognitive processes

The study was designed to define some of the elements of cognitive impairments evident in unmedicated Parkinson's disease (PD) patients. Unlike patients with progressive dementias such as Alzheimer's disease, untreated, mildly to moderately affected PD patients are efficient at accessing previously acquired knowledge. They also can learn and remember information that can be processed "automatically," using operations requiring little cognitive capacity. However, PD patients demonstrate relatively specific cognitive impairments for effort-demanding processes. These findings are clinically useful, but also help define the boundaries of psychobiologically distinct cognitive (memory-learning) processes.

Heart rate and blood pressure response to several methods of strength training

This study was undertaken to determine heart rate and blood pressure responses to various exercises used during strengthening programs. Heart rate, blood pressure, and pressure-rate product (systolic blood pressure X heart rate) were determined for five subjects performing five different strength-training exercises at 75 and 100 percent of maximum voluntary contraction (MVC). The exercises included isometric and isokinetic exercises and isotonic exercises with free weights. Systolic blood pressure, diastolic blood pressure, and pressure-rate product increased significantly with all exercises; heart rate increased with most of the exercises. In some, but not all, of the exercise sessions in which two measurements were made at different times, heart rate, blood pressure, and pressure-rate product were higher for the second measurement. Pressure-rate product was significantly higher for the exercises performed at 100 percent of MVC than for those performed at 75 percent of MVC. The isokinetic exercise performed at 100 percent of MVC produced the highest pressure-rate product.

Serum dopamine beta hydroxylase in children with neuroblastoma

Serum dopamine-beta-hydroxylase (DBH) activity has been reported to be raised in some patients with neuoblastoma but this has been challenged. We have studied serum DBH levels on 26 children with neuroblastoma and 58 age-matched controls. Only in 2 patients were the levels higher than in the controls, and then only transiently. In both, the rise in DBH levels could be accounted for by the transfusion of adult blood. Serum DBH levels in children with neuroblastoma were unrelated to the response of this neoplasm to treatment or to urinary catecholamine output and thus are unlikely to have any value in diagnosis or as a marker of tumour activity.

Relation of single unit properties to the oculomotor function of the nucleus of the basal optic root (accessory optic system) in chickens

Single unit recordings in the nucleus of the basal optic root (nBOR) of the accessory optic system in chickens suggest that it has a role in vertical stabilizing eye movements. Cells have unusually large receptive fields and never respond to small stationary stimuli. They respond best to large richly patterned stimuli moving slowly (2-4 degrees/s) in vertical directions. Cells responsive to upward movement tend to be located in the dorsal portion of nBOR, which projects to motor areas producing upward eye movement, whereas cells responsive to downward movement tend to be located in the ventral portion of nBOR, which projects to motor areas producing downward eye movement; this suggests that these synapses onto oculomotor neurons are excitatory. In many nBOR units, the preferred and null directions are not opposite to each other. These directional asymmetries seem to be correlated with other properties of the units in a manner that supports the idea that the accessory optic system is arranged according to a vestibular coordinate system. This finding complements the abundant anatomical and physiological evidence linking the accessory optic system to the vestibular system.

Self-help groups in a premature nursery-a controlled evaluation

This study examined the effect discussion groups, held in a neonatal intensive care unit with parents of very small premature infants, had on various measures of later parenting competence. Twenth-eight families who met for seven to ten weeks with a nurse co-ordinator and a "veteran mother" who had given birth to a premature infant within the past year were compared with 29 control families. Parents who had participated in the groups visited their infants significantly more often in hospital than did the control parents. They also touched, talked, and looked at their infants in the en face position more during their visits, and rated themselves as more competent on a number of infant care measures. Three months after discharge of the infants, group mothers continued to show more involvement with their babies during feedings and were more concerned about their general development. The implications of such self-help groups for the later development of high-risk premature infants is discussed.

Patients, charts, and orders: keeping track

A simple, inexpensive system for keeping track of charts, orders, and patients in a busy emergency department is described. All orders, except the most urgent, are communicated in writing. A secretary relieves the nurses of secretarial duties, and functions as coordinator of laboratory work and communications. A traffic board, using magnetic markers, allows instant visualization of the state of the department. Swift movement of patients from room to room can occur without losing track of the patient or his chart. A system of six discrete chart stations is used, each denoting a separate task to be done. The chart moves in an orderly manner through stations, giving the staff "at a glance" information about what must be done and how well the department is processing patients. A scribe option is employed in overload conditions, allowing a substantial increase in patient processing.

Contusion angle deformity in prizefighters

Ophthalmic examinations of 55 retired boxers showed nine eyes with contusion angle deformities and no cases of secondary glaucoma due to the trauma, despite an average duration of 33 years since injury. The subjects with chamber angle recessions had more proptotic eyes (average, 19.7 mm) than those without recessions (average, 17.9 mm). The difference between the means was not significant (P less than .05).